The present invention relates to a rear projection screen or a light transmission screen which is suitably used for a video projection television, micro film-reader, or the like.
An example of a rear projection screen of this type is shown in FIG. 9, which comprises a rear projection screen or a so-called lenticular screen having a transparent medium 30 formed therein with micro projections such as, lenticular lenses 31 on one surface of the transparent medium (Japanese Patent Laid-open No. 54-134431).
Light rays from a projector are projected onto one surface (incidence surface X) of the transparent medium, and an image is observed on the other surface (viewing surface Y) of the transparent medium. That is, the projected light rays are focused on the viewing surface by each lenticular lens element 31 at a part around the optical axis of the lenticular lens element 31. In order to improve the contrast of the image, the screen is provided with stripe-like shade coatings 32 (hereinafter referred to "ambient light absorbing layer") located in an area (hereinafter referred to "no-light focusing area") of the viewing surface excluding the light focussing position and extending parallel to the longitudinal axis of the lenticular lense.
FIG. 10 and FIG. 11 show other examples of prior art, where the coating of the ambient light absorbing layer 32 is facilitated by providing projections 33 or hollowes 34 on the viewing surface. (Japanese Patent Laid-open No. 56-38035).
FIG. 12 shows further another example of prior art, where lenticular lenses are formed on both sides of a screen, and the coating of the ambient light absorbing layers 32 is facilitated by providing projections at a level higher than the top of the viewing side lenticular lens 35 (Japanese Patent Laid-open No. 58-147318).
However, the rear projection screen shown in FIG. 9 has a disadvantage that the ambient light absorbing layers have low adhesion and are liable to come off because they are coated on flat surfaces. In the case of rear projection screens as shown in FIGS. 10 and 12, in which ambient light absorbing layers 32 are coated on the top surfaces of projections 33 but are not on the side surfaces, thereof, no dark appearance are given as viewed laterally, and therefore there has been such a disadvantage that ambient light impinging upon the viewing surface reduces the contrast ratio of the image.
The rear projection screen shown in FIG. 11, where hollowes 34 are formed for receiving ambient light absorbing layers, causes a disadvantage that it is difficult to make clear the border lines of the light absorbing layers 32, in particular if the lenticular lenses are formed between the ambient light absorbing layers 32.